Supersonic aircraft and wing structure therefor



Feb. 5, 1952 A, A.` GRIFFITH ysuRERsoNIc AIRCRAFT AND WING STRUCTURETHEREROR 5 sheets-sheet 1 Filed Feb. 21, 1949 l l l uw Nw WMU? -WUMMHHHHMH-- 1..........\.\--

' I /Nre/vroz l ALAN GQ/Ff/TH sURERsoNIC AIRCRAFT AND WING STRUCTURETHEREFOR Filed Feb. 21, 1949 A. A. GRIFFITH Feb. 5, 1952 3 Sheets-Sheet2 Feb. 5, 1952 A. A. GRIFFITH SUPERSONI-C AIRCRAFIT AND WING STRUCTURETHEREFOR Filed Feb. 21, 1949 3 Sheets-Sheet 3 Patented Feb. 5, 1952UNITED .STATES .'s U1] fERsoN1cAIRcRAFr-Ann l l STRUCTURE THEREFOR,

vAlan Arnold Grfith,l)erby,England, assignor-fto Rolls-.Royce Limited,Derby, England, a .British Application'v February 21, 1949, Serial N o.71,603' i-InGreat'Britain September 7, 19458- s'elaims. (c1. 244-15)invention being additionally applicablejto pilotl and-passenger carrying`aircraftof the supersonic `vThe primary object of theinventicnistopro-V vide-'asupersonic aircraft which is `propelled by an v-airfconsuming power plant, in which `overall drag; and the structure weightof the. aircraft erellow.A t

:According to l'this invention, the wing structure of a supersonicaircraftris made hollow, and substantially the whole of .the yleading`edge constitntes'an` air intake to an air consuming propulsive system.The latterr may .for example be a gasL turbine *jet propulsion engine,or a .ram-.jet inwwhich. air is-compressed .due to .the -'forward speedof flight', 'fuel being burnt in the compressed air to'produce .ahighvelocity propelling jet. Preferably',v the maximum thickness of the`wing ateach chordal location is at the .leading edge which provides .theair intake, and the air passage-constituted inthe thickness of the wing.is

preferably divided to provide a number of Vducts each'ofafdiffusingwnature' leading into 'the propulsivesystem. f f Y In a wingflying supersonically part of the drag isfattributable to the shockwavewhich arises at Mach numbers in excess of unity, such shock :L

wave drag being approximately proportional to thesquare ofv thethickness/chord ratio of the Wing. fConsidering -a supersonic wingentirely` from the -aerodynamic point of view, it has hitherto beenconsidered desirable to kuse very thin wings to obtain a maximumlift/drag ratio under Vsupersonic lightconditions. The design of suchwing structures leadsto excessive weight.

Another object of the present invention is to avoid the use of extremelythin wings in supersonic aircraft having air consuming power plants,without producing a correspondingincrease in the shockwave drag of theaircraft. y. I. Another object of this invention is to make it possibletor use a supersonic wing of .greater thickness/chord ratio vand thusreduce 'the structural Weight, without increasing'thetotal dragl of theaircraft under powered' flight.

Thus a supersonicaircraft-wing structure in accordance with theinventionv provides that the wave kdrag,associated withvthe wingthickness is for the most. .Dart in the form of intake shock Wave. 'I'hecorresponding drag necessarily accompanies; :the `.intake ofVVpropulsive air.. whether the intake is combined with the wing,asyxrthe presentinventionpor is separate.l tt-followsthat by combiningthefwing and intake in themanner of the invention, the wavedrag normallyassociated with a thick wingis `avoided so that ineiect the wingisaerodynamically thin but structurally thick.

Two embodiments of the invention willnow-:be described in order that theinvention may fbe more clearly understood, reference beingv had 'to theaccompanying-drawings, Aof which:

Figure 1 is a planof'asuperlsonic aircraftem'- bodying the invention;

Figure 2 is va front .elevation ofthe aircraft.

illustrated lin Figurefl, tota.v .larger scale; Figure` 3 .is a partside :elevation: :tofthe lsame scale as Figureff2; v A

.Figure 4 isapart :isometric view-nf'r the Wing structure ofthe aircraftillustratedl :ln-Figure 1l, to a .still larger scale.; Figures 5 :andGuaresectional views `on the `lines 5 5 and 6 6 offfFigurel; .and-Figure '7 is a plan of anotheraircraft .embodying the invention.

The aircraft illustrated in Figures 1-6..fiS/f;a

supersonic aircraft ypropelledxby va gas-turbine plant, vthe .designbeing .suitablefor iiightiata Mach number of approximately 3 andcomprisesv essentially va fuselage structure. -I l)l withptail em.-pennage having Stabilising andfor steering'ns Il The nose portion .l2 ofthe fuselage can .constitute Va warhead in the caseofua-.guided-mis'sile or may provide pilot accommodationof-a pilotedaircraft. The nose portion is;V of sucientlength to "provide that` theshockwave formed. ibyrthe leading edge, whenythesfaircraft.is;iiyngeatdesignedflightspeed, is at anfanglegartofthe.longitudinalzaxis oftheyaircraftzsuch that. Vthe :shock wave..c1ears the .wingtipszas-.indicated byzthe chain dotted lines. 1 v j. .1 The propulsive .systemcomprises.afgas-fturbine jet propulsion engineaccommodated-initheffuseflage l 0 .including .an. air compressor. L3 delivering air tocornbustionequipment I4 in-,which fuel` is burnt, the products .of combustonrpassnsto. .the turbine l5 which drivesthel `compressor i3 through shaft, I6.fIhe.A exhaust iiow from. the turbine passes ,through exhaust `duct vl l.'a pro-f pelling nozzle I8. kThe air-.intake;togt he gasturbineg engineis providedbrchannels I9.y formed.; between upper and lower Surfacesyof.vthe .,wingsf20. p .y As will be seen by particular reference to Figures2 andfl .thevupper and lower zsurfacesof each wing includes: an outer;skin. 2 l andl inner skin, 22.- 'Ifhe outer skins are aerodynamicallysmooth and'provide the requisite aerofoilgshape whilst ther-inner skinsyaref-arched betweenwebs 23, .which Vspace the upper and 1ower-Wing;surfaces. apart providing Structural strength andalso defining the. sides;of .fclnamels`4 indicatedi-.et L9..

It will beobserved thatthe channels I9 also make ananglefofapproximately a to [the longitudinal axis of the aircraft.

The thickness/ chord ratio may be substantially.

uniform spanwise, avoiding anv excessive increase of this ratio at theroot, the trailing edge 29AM of the wing lying substantially paralleltothe walls of the channels I9. {Ihusfora high speed 1 aircraft asillustrated the-aspect ratio Vof the` slightly forward so that the'deflection of the air` y by the intake shock wave turns the air smoothlyinto the channels I9 through the intake openings in the leading edge ofthe wing, that is betweenthelea-ding edges of the upper and lower wingsurfaces, seen in Figures 2 and 4.

The, maximum thickness of -the wing is at its leadingedge, Vand due tothe increased thickness o fthewing towards the root the passages I9 willbe of a diffusing nature as between their eng tries and their exits intothe air entry duct to the compressor. The latter entry indicated at 24leads from an apertured bulkhead 25 which receives the exit ends of thechannels I9. The diffusing nature ofthe lducts I9Ycan best beappreciated from Figures 5 and 6 Vwhich show sections iof one duct atdifferent places along its length,` the: section `shownH-in Figure 5being smallerinarea ,andnearen-the leading edge of the wing than thesection in Figure. Y i

At the junction of the leading edge of the wing 2 0 `with the fuselageI0, suction slots 26 are provided to reduce disturbance in the airintake which might otherwise arise from the presence of the nose portionI2.; Air abstracted by means of a suction pumpfrom this area may beejected rearwardly to assist in the propulsion. of the aircraft.

vIt will be seen that the invention provides wings which arestructurally Ystiff in bending and torsion,V and though of relativelygreat thickness/ chordratio the aerodynamic shock wave drag attributableto lsuch relatively great ratio can be assessedas including the intakedrag associated with'the air entry tothe gas turbine engine.

In addition, the space vwithin the.fuselage,

above and below .the air entry passages provides space 211 (Figure .3)for the fuel, approximately at the centre of gravity of the aircraft.'Figure .'Ifshows another embodiment of the invention.fwhich isgenerally similar tov that de scribed above,.but: has` two gas-turbineengines 30, 3I side by side. The engine 30n receives air from the ducts32 in the wing 33, and the'engine 3| receives air from the'ductsr34 inthe wing 35. The exhaust from .both engines isejected through apropulsion nozzle common to both of them.

The inventionvis also applicable to the fiying wing structures in whichthe fuselage structure blends intothe upper: and lower surfaces ofthewing and the tail empennageissometimes obviated. f l It is to beunderstood .that the aboveembodiments are not intended to limit theinvention, the scope of which is defined in-the appended claims. -Iclaim: 1.In a supersonic aircraft, the combinationfof a fuselage, andair-consuming power-plant in said fuselage, a wing-structure comprisinga wing on either side of said fuselage each of which wings `has arootrjoining it tosaid fuselage, said Wings each comprising an `uppersurface-member to provide an upper-defining surface and alowersurface-member tov provide alower defining sur- 4 face, said surfacesbeing joined together at a trailing edge commonto bothlofithe'm.Vv andeach of said surface-members having a forward edge spaced from the othersurface-member over substantially the whole length of the edge, and anVair-passagev in each of said wings extending from "said forward edgesto said power-plant which air passages` are Vof divergent cross-sectionfrom said forward edges.

2. An aircraft according to claim 1, wherein said surface-members arespaced apart by webs i extending continuously from said forward edgesinto said roots, said webs constituting with said surface-members theboundaries of a plurality of air-ducts within each of said air-passages.

An.y aircraft according to claim 2; wherein said trailing edge of eachof said wings is sub-5 stantially parallel with said web s in thatwing.V 4. .An Yaircraft according 4to claim 1 wherein saidrforward.edgesV are swept slightly forwardly from said root. 5. In a supersonicaircraft the combination of a fuselage, an air-consuming power-plantinsaid fuselage, a wing-structure for said aircraft com? prising a wingon Yeither sideof said fuselage, each of which wings has a root joiningit to sai d fuselage, said wings each comprising an uppersurface-member` and a lower surface-member, said surface-memberscomprising each an outer skin and an inner skin, said outer skinsprovid: ing respectively an upper defining surface and a, lower deningsurface of said wings, said denning surfaces being joined together at atrailing edge common to both of them, said surfacemem-4 bers having eacha forward edge spaced from the other surfacemember over. substantiallythe whole length of the edge, saidinner `and outer skins of each of saidsurface-members being joined together at said forward edge o f thatmem-t ber, an air-passage in Veach of said wings-extend: ing from saidforward edges of said power-plant, and webs attached to said innerskinsand extending within each wing continuously from said leadingedges intosaid root of the wing inwhich it extends, said webs constituting withsaid inner skins of ,said surfaceemembers, the ,Walls of a plu;y ralityof air ducts within each ofV said air passages each of which air ductsis of divergent crosssection, said inner skins being arched betweenadjacent webs. i 6. An aircraft according to claim 1 wherein the upperandlower surface members converge towards each other from the forwardedgeso that the maximum thickness of said wing struct ture is betweentheforward edges of said surface members. l

- ALAN ARNOLD GRIFFITH.

REFERENCES o1TEn- The following references`v are of record iii-'the leofthis patent:

UNITED STATES PATENTS Aircraft Engineering, issue of March 1949,page'17-.r 2,215. i'

